Locking device for handles



May 7, 1929. F. A. JIMERSON LOCKING DEVICE FOR HANDLES Filed Dec. 20,1926 INVENTOR. fivoa/slilimersa/z.

M'J'ATT NEY.'

Patented May 7, 1929.

UNITED STATES PATENT OFFICE.

FRANCIS A. JIMERSON, 0F ATHENS, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RANDCOMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

LOCKING DEVICE FOR HANDLES,

Application filed December 20, 1926. Serial No. 155,983.

This invention relates to pneumatic tools but more particularly to adevice for securing certain parts of the tool in their relative posi-'tions.

One object of this invention is to enable the front head of the tool tobe held securely in place relative to the cylinder din-ing the operationof the tool and similarly to hold the cylinder securely in place withreference to the back head or hood.

Further objects will be in part obvious and in part pointed outhereinafter.

The invention consists of the features of construction and combinationof elements substantially as hereinafter described and more particularlypointed out in the appended claim and illustrated in the accompanyingdrawings, in which Figure 1 is a longitudinal partial sectionalelevation of a pneumatic hammer tool constructed in accordance with thepractice of the invention.

Figure 2 is a plan view in section taken through Fig. l on the line 22looking in the direction of the arrows, and

Figure 3 is a plan view in section taken through Fig. 1 on the line 33looking in the direction of the arrows.

Referring to the drawings A is the cylinder of a pneumatic hammer toolhaving the front head B and the back head or hood C. Blows of impact aredelivered to the drill steel S by the reciprocating hammer piston Dwhich is actuated by motive fluid entering the tool atld and distributedby a valve (not shown) on the back head or hood C. The admission ofmotive fluid is controlled by a throttle not shown) operated bya'trigger F in the handle G. The front head B has an internally threadedrecess into which is screwed a corrcspondingly threaded portion of thefront end of the cylinder A. The rear end of the cylinder A isexternally threaded and is screwed into a threaded recess in the backhead C.

The vibration of the tool during its operation frequently causes thethreaded portions above referred to to become unscrewed and it is anobject of this invention to prevent this accidental unscrewing. To thisend longitudinal slots T are provided in the cylinder A and the fronthead B. A helical spring J coiled about the cylinder A has its ends Kbent so as to lie parallel to the axis of the spring coil. After thefront head B is screwed into place one of the ends K of the spring J isplaced in one of theslots T on the cylinder A. The tension of the springis then increased by giving the free end of the spring a partial turn.The free end is then inserted into one of the slots K on the front headB. The tension of the spring acting through the slots on the cylinderand front head constantly tends to screw these parts more tightlytogether.

In a similar manner a helical spring J surrounds the cylinder A and hasits longitudinally extending ends K and L disposed in the longitudinalslots O and P of the back head C and the cylinder A respectively.

A cylindrical exhaust deflector or guard Q is mounted over the spring Jand upon the cylinder A. The upper end K of the spring J projectsthrough a slot R in the flange U of the guard Q. In assembling the toolthe end L of the spring J is placed in the slot P and the spring iscompressed by grasping the deflector or guard Q and holding it down wardwhile the hood C is screwed into position. After the hood C is screwedinto position the guard Q is grasped and twisted so as to produce atorsional stress in the spring J so that the said spring is undercombined torsion and compression when in its operating position. Thecompression holds the guard Q, up against the front end ofthe hood G andat the same time keeps the ends K and L of the spring J engaged in theirrespective slots. The torsion tends to keep the handle screwed tightonto the cylinder or barrel A. I claim: In a pneumatic tool thecombination of a cylinder and a back head, a reciprocating piston insaid cylinder adapted to be operated by pressure fluid, threadedportions on said back head and said cylinder whereby said back head andsaid cylinder are adapted to be screwed together, an exhaust port insaid cylinder, a helical spring coiled about one 0i inder and said backhead to maintain said said threaded portions, longitudinally exthreadedport-ions screwed together, said 10 tending ends on said helical spring,longituspring guard covering said exhaust port and dinal slots in saidback head and in said oyl deflecting exhaust motive fluid.

inder, a spring guard adapted to engage one In testimony whereof I havesigned this end of said spring for tensioning said spring, 1specification.

said longitudinally extending ends adapted to engage said longitudinalslots in said cyl- FRANCIS A. J IMERSON.

